Method of cleaning accumulated material from a slot

ABSTRACT

A system for removing accumulations of liquid and fine solid materials from between two movable contacting members that seal the accumulated materials in a slot where they are blasted by air to a receptacle. The blast is timed to occur when the slot is sealed between the member which carries it and a second member moving over it. An actuator releases air when the slot is sealed.

United States Patent 1191 Egnaczak METHOD OF CLEANING ACCUMULATED MATERIAL FROM A SLOT [75] Inventor: Raymond Keith Egnaczak,

Williamson, NY.

[73] Assignee: Xerox Corporation, Rochester, NY. [22] Filed: Apr. 19, 1972 [2]] Appl. No.: 245,525.

Related US. Application Data [62] Division of Ser. No. 876,715, Nov. 14, 1969, Pat. No.

[52] US. Cl 134/21, 134/37, 100/90, 15/308, 355/15 [51] lint. Cl 1308b 5/02 [58] Field of Search 15/302, 306, 306 A, 308,

[56] References Cited UNITED STATES PATENTS 1,908,519 5/1933 Leonard l00/174 X [111 3,821,027 lune 28, 1974 3,003,176 10/1961 Goyette 15/308 x 3,468,242 9/1969 Schaffrath.... 100/90 x 3,686,035 8/1972 Riley 15/308 x Primary Examiner-Morris O. Wolk Assistant Examiner-T. W. Hagan 5 7] ABSTRACT A system for removing accumulations of liquid and fine solid materials from between two movable contacting members that seal the accumulated materials in a slot where they are blasted by air to a receptacle. The blast is timed to occur when the slot is sealed between the member which carries it and a second member moving over it. An actuator releases air when the slot is sealed.

7 Claims, 4 Drawing Figures ATED CROSS REFERENCE TO RELATED APPLICATION tive to it, the materials are pushed ahead of the interface area. What generally happens with a liquid andsome solid materials is that a major portion of the material is pinched ahead of the nip between the two moving members forming a bead or a large accumulation at the lead edge in the direction of approach of the members. If the bead is allowed to accumulate in front of the approaching devices, it may have dilatorious effects upon the apparatus in which it is found. One particular class of apparatus that sometimes encounters this accumulation of materials are hard copy imaging systems. One such system known as photoelectrophoresis is used for forming black and white or full color images. The basic processes and apparatus are disclosed in US. Pat. Nos. 3,384,565; 3,384,566 and 3,383,993. Since this discovery, various apparatus have been developed to utilize the process disclosed therein. The basic system utilizes photoelectrophoretic particles which migrate in image configuration providing a visual image at one .or both of two electrodes between which the particles are placed in a suspension. The particles are photosensitive and apparently undergo a net change in charge polarity or a polarity alteration by interaction with one of the electrodes upon exposure to activating electromagnetic radiation. The particles will migrate from one of the electrodes under the influence of an electric field when struck with energy of a wavelength within the spectral response of the particles.

Apparatus has been invented to better utilize the above process in an automated system shown in US. Pat. No. 3,427,242 issued Feb. 1 l, 1969 which described a continuous apparatus embodiment of the above process. Further, equipment has been designed utilizing flat and rotary imaging members to form images with the above process all of which can be improved by the invention herein.

Another system that can be improved by the invention described herein is xerographic imaging where an image is formed and developed on the surface of a photoconductor by electrostatic means. The basic xerographic process as taught by C. F. Carlson in US. Pat. No. 2,297,691 involves placing a uniform electrostatic charge on a photoconductive insulating layer, exposing the layer to a light image to dissipate the charge in the areas of the layer exposed to the light and then developing the resulting latent electrostatic image by depositing on the image a finely divided electroscopic material referred to in the art as toner. The toner is attracted normally to those areas of the photoconductive layer which retains a charge thereby forming a toner image corresponding to the electrostatic latent image. The toner image may then be transferred to a support the photoconductive material. It is with these developsurface and permanently affixed thereto by heat or vapor or the like. It may also be that the photoconductive layer itself serves as the final support medium in which case no transfer step is required.

Many varied methods and apparatus have been designed for developing the latent electrostatic image. Among them are liquid development systems. In conventional liquid development systems an insulating liquid vehicle having finely divided solid material dispersed in it contacts the surface in both charged and uncharged areas but is maintained on the photoconductive surface in a relation to the latent electrostatic image charge pattern thereon. Disclosed in. US. Pat. No. 3,084,043 is a liquid development system known as polar liquid development. Another development technique is disclosed in US. Pat. No. 3,285,714 where an aqueous developer uniformly contacts the entire imaging surfaceand selectively wets only the charged areas of the imaging surface.

The liquid developing techniques as well as some dry development techniques often accumulate excess development materials and carriers along the surface of ment systems that the invention described herein is a helpful improvement since the developer liquid is loaded onto the applicator surface indiscriminately in excessive quantities. As the developer liquid on the'surface of the applicator is brought into contact with the photoconductive surface, it squeezes into a head at the exit'of the nip between the two surfaces. This material is not fully utilized in forming a visible image on the photoconductive surface and it would be helpful to remove the material at least after an image is formed to prevent residual material from interfering with later images to be formed.

Other apparatus can be contemplated such as schematically shown in FllG. ll hereinafter which uses segments of cylinders in its operation. If the accumulated materials are allowed to ride along the segment, they will eventually leak, drip or fall into the interior of the segment and interfere with the internal mechanism or general operation of the apparatus utilizing such a cylinder segment. Therefore, it becomes important to eliminate accumulations of materials from reaching the edge of segments of cylinders or from continually revolving around a cylindrical or other shaped members.

A further object of this invention is to improve sys-- terns for removing accumulations of materials between two moving members cyclically and automatically. An-

other object of this invention is to prevent accumulations of materials from interfering with further images of an imaging system.

These and other objects of this invention are accomplished by providing a timed air blast through a slot on one of two interfacing surfaces. The air blast forces materials trapped in the slot, between the two mated surfaces, along the length of the slot to a container. The air blast is effective when the slotted member is contacted at the slot by another member thereby sealing the slot.

The invention herein is described and illustrated in a specific embodiment having specific components listed for carrying out the functions of the apparatus. Nevertheless, the invention need not be thought of as being confined to such a specific showing and should be construed broadly within the scope of the claims. Any and all equivalent structures known to those skilled in the art can be substituted for specific apparatus disclosed as long as the substituted apparatus achieves a similar function. It may be that other processes or apparatus will be invented having similar needs to those fulfilled by the apparatus described and claimed herein and it is the intention herein to describe an invention for use in apparatus other than the embodiment shown.

The above and other objects and advantages of this invention will become/apparent to those skilled in the art after reading the following description taken in con junction with the accompanying drawings wherein:

FIG. 1 schematically illustrates an embodiment of a machine for forming photoelectrophoretic images;

FIG. 2 is a side view of the member embodying the invention with hidden parts dotted;

FIG. 3 is a sectional view taken along line 3-3 of 3,384,565; 3,384,566 and 3,383,993 referred to above. 1

Certain terms referred to therein are adopted herein such as the injecting electrode so named because it is thought to inject electrical charges into activating photosensitive particles during imaging. The term photosensitive refers to the property of a particle which, once attracted to the injecting electrode will alter its polarity and migrate away from the electrode under the influence of an applied electric field when exposed to activating electromagnetic radiation. The term suspension is used here to refer to a solid suspended in a "liquid carrier. The term imaging electrode describes that electrode which contacts the injecting electrode through the suspension and which once contacted by activated photosensitive particles will not inject sufficient charge into them to cause them to migrate from the imaging electrode surface. The imaging zone is that zone between two electrodes where photoelectrophoretic imaging occurs.

Briefly, for photoelectrophoretic imaging to occur these steps take place: (1) migration of the photosensitive particles toward the injecting electrode due to the influence of an external field, (2) generation of charge carriers within the particles when struck with activating radiation, (3) particle desposition on or near the injecting electrode surface, (4) phenomena associated with the forming of an electrical junction between the particles and the injecting electrode, (5) particle charge exchange with the injecting electrode, (6) electrophoretic migration toward the imaging electrode and (7) particle deposition on the imaging electrode. This leaves a positive image on the injecting electrode. The Machine Components Referring now to FIG. 1, a preferred embodiment for an automated machine to produce images according to the aforementioned process is shown. An injecting shaft 3. The injecting electrode 1 is made up of a layer of optically transparent glass 4 overcoated with a thin optically transparent layer 5 of tin oxide or other electrically conducting material. A particular material suitable for this electrode is available under the name of NESA glass manufactured by Pittsburgh Plate Glass Co., Pittsburgh, Pa. The injecting electrode 1 is formed as a portion of a cylinder housed within the metal housing frame 2.

The machine shown schematically in FIG. 1 is positioned where the injecting electrode cylinder portion is about to be rotated in a predetermined path to a cleaning station labeled A whereat a plurality of cleaning members such as belts 6, 7 and 8-contact the'conductive surface 5 of the injecting electrode. On the opposite side of the injecting electrode held stationary within the machine frame are lamps 9, 10 and 11 juxtaposed to the belts 6, 7 and 8 respectively. When activated, the lamps send flood light illumination through the transparent injecting electrode at the contact areas between the electrode and the cleaning belts. Each of the belts are activated by oneof the cylinders 12, 13 and 14 to contact the injectingelectrode 1. These cylinders operate to press the belts against the conductive surface of the injecting electrode in order to clean it.

The next station in the pathof movement of the injecting electrode is the imaging station B. Here, on the first pass of the injecting electrode 1 through station B the first imaging member, the imaging electrode 16 interfaces with the conductive surface 5 of the injecting electrode 1.

The optical system at station C projects an image to I the imagingzone between the electrodes 1 and 16 at station E. The optical system has a lamp carriage l7 journaled at an axis 18 to oscillate in a path indicated by the arrows. A document 20 is positioned at the platen 19. The lamps are shown at the start of scan position and as the injecting electrode 1 passes through the imaging area at station B the lamps move across the platen 19 projecting an image at station B through suitable mirrors 21-23, a lens 24 and the transparent electrode l.

The imaging electrode roller 16 moves in rolling interface relation with the conductive surface 5 of the injecting electrode 1 and functions both to supply suspension to the injecting electrode and to image that suspension between the injecting electrode surface 5 and the surface of the electrode 16.

The injecting electrode continues to rotate at a constant velocity through a complete rotation of the predetermined path. It travels without interacting with any elements located around the periphery of the path until it again reaches station B at the imaging zone. Now,

, however, the injecting electrode 16 has been moved trode'29 at the imaging zone at the imaging station 18 of the machine. The second imaging electrode 29 moves in rolling interface with the injecting electrode surface as that surface passes through the imaging station B. At this time the original 20 on the platen T9 is again illuminated by the scanning lamps 33 at the optical system station C. The scan is synchronized with the movement of the injecting electrode to project a flowing image in registration with the first projection and moving at the same rate as is the surface 5 at the imaging zone.

The injecting electrode 1 then passes into the transfer station D. At station D is a transfer roller Ail. A sheet of support material held in the supply tray All is lifted therefrom and is carried through a vacuum transport 42to the transfer roller 4%. It is gripped by a gripper mechanism ll-3 on the transfer roller did and rotatedto the injecting electrode ll passing at station D. Before the sheet 54 contacts the surface 5 of the injecting electrode ll it is moistened with a liquid that will aid in transferring the particles of the suspension on the surface 5. The wetting is accomplished by a wetting bar d5 rotated in a poll of suitable wetting material held within a tank 46. The transfer member Ail rotates the support material 4'4 in rolling contact with the surface 5 of the injecting electrode l under the influence of a suitable electric field causing the particles forming the image on the injecting electrode to be transferred to the support material. The support material is removed from the transfer member by picker fingers 47 and a release mechanism on the grippers. Next it is carried on a vacuum transport 45 to a fixing station E where it is heated or otherwise fixed to form a permanently bonded image on the support material which is then deposited in some suitable receptacle.

FIGS. 2 and 3 show the injecting electrode housing and assembly as viewed from the cleaning station A in FIG. 11. The light shield M5 has an aperture slot M6 at the imaging station of the machine. The aperture M6 is a field stop near the image plane of the optical system to limit the image area illuminated at the imaging electrode. At the opposite end of the light shield is an aperture l4l7 through which the light rays from the optical system pass to reach the image plane. The light shield is used to prevent ambient light from reaching the imaging station and interfering with the illumination used for forming the images. The light shield, light mounting brackets and those members associated therewith are stationary within the machine andonce positioned according to the optical path requirements do not move during the operation of themachine. Rotating around the light shield and the apparatus appended thereto is the injecting electrode and its associated housing.

The injecting electrode is held in an electrode support referred to as the drum frame Mounted on the drum frame 115% is an overframe ll5ll.

The frame T50 is rotated about fixed shafts T53 and 15d which fasten to the light shield 1145. The ends of the frame ll5tl are closed by two end caps 155 and T56 which are each mounted on a bearing housing, 157 and 158 respectively, on each side of the assembly. The bearing housing T57 is mounted through bearing 1159 to the machine support frame llbfi shown dotted herein for reference. a

The bearing housing and end cap are mounted to the fixed frame by bearings M2 and 1153 to permit rotation of the cylinder frame 1150 and injecting electrode around the fixed shaft 153. The. fixed shaft 1153 has a flat llfi ll at the end thereof which for location within the machine support frame ldtl to set the aperture 146 in the proper position for imaging at the imaging electrode-station.

On the other side of the cylinder frame 15% is the fixed shaft 1154i. This shaft is in fact a hollow tube permitting air fiow therethrough. An air fitting 165 is at tached to the outboard end of the fixed shaft to couple to an air supply for bringing air through the hollow portion lob of the fixed shaft 15%. The hollow lbb connects with an angular groove 1167 which in turn connects to a slot H in the bearing housing 155. O-rings M9 and 1170 effectively seal the passage from air leaks during operation of the system. The slot 1165 feeds into a piston housing ll7ll which comprises a backing mem ber 172, an air chamber 173, a piston valve seal T74, piston valve 175 and return spring T76. Also cut into the piston housing ll7ll is a chamber 1177 which connects to the cleanout'slot T in the'glass support member M5.

A register pin 1179 is located in a hole within the bearing housing 155. The bearing housing rotates about the fixed shaft 154!- through two bearings lfitll and lfill. The bearing housing T53 is formed from a long hollow tube with a tapered surface 152 near the pin T79. The gear box l brings the power supply l9tla used for rotating the injecting electrode housing. The nut T53 draws the shaft 157 into tight contact with the taper T52 of the bearing housing and ensures that the slot res covers the register pin 1179 for positive driving of the inject-' ing electrode drum assembly.

On the gear box 1154 is a valve actuator trigger 189 having a solenoid we powered by the power supply Wfia which is programmed to trigger the piston rod 191 to strike the piston valve I causing a burst of air to flow through the cleanout slot 175. This sequence occurs when the cleanout slot 175 is contacted by either of the imaging electrodes 16 or 29 or the transfer roll 4M) which forms a seal with the slot to ensure that all of the materials forced into the slot will be air blasted completely through and out the other end thereof.

A switch T92 makes a contactwhen struck by the register pin T79. This actuates the solenoid as described above. A second switch (not shown) is located to actuate the solenoid 11% when the slot 175 is sealed at the transfer station D when the piston valve 1175 is contacted by the piston rod 193 shown in FIG. 2 positioned in the actuator trigger w ll.

The materials and air forced through the cleanout slot 175 strike a deflector tube T95 and are carried into a receiver container 1% where the materials can be stored or removed at the will of the machine operator. The gases for operating the system may be supplied by an convenient means such as the air cylinder T97 schematically shown in FIG. 3. Of course, any equivalent functional mechanism can be used and any convenient gases employed. Air and air cylinders are used as illustrations for functional equivalent gases and-supply systerns.

I While this invention has been described with reference .to the structures disclosed herein and while certain theories have been expressed, it is not confined to the details set forth; and this application is intended to cover such modifications or changes as may come within the purposes of the improvements and scope of the following claims. What is claimed is: l. A method for removing accumulated material including:

providing at least two surfaces, at least one having a slot therein, and an accumulated material receiver container; contacting two of the surfaces together including the one having a slot therein;- moving the surfaces to accumulate materials therebetween; bringing the accumulated material into the slot; sealing the length of the slot with the surfaces thereby trapping the accumulated materials in the slot; forcing positive pressure gas through the slot whenever the slot is so sealed at a velocity sufficient to drive the accumulated materials through, and not from, the length of the slot and out one end thereof into the accumulated material receiver container.

2. The method of claim 1 including programming the forcing of gas to occur when the length of the slot is sealed.

3. The method of claim 1 including moving at least one of the surfaces in-interfacing rolling relation with another so that the accumulated material is pushed at the nip between the moving surfaces.

4. The method of claim 1 wherein the gas forced through the slot is in the form of a burst of gas.

5. The method of claim 1 wherein the gas is forced from one end of the slot to the other across the length of the slot.

6. The method of claim 1 wherein the materials accumulated within the slot are liquids.

7. The method of claim 1 wherein said gas forced through the slot is air. 

2. The method of claim 1 including programming the forcing of gas to occur when the length of the slot is sealed.
 3. The method of claim 1 including moving at least one of the surfaces in interfacing rolling relation with another so that the accumulated material is pushed at the nip between the moving surfaces.
 4. The method of claim 1 wherein the gas forced through the slot is in the form of a burst of gas.
 5. The method of claim 1 wherein the gas is forced from one end of the slot to the other across the length of the slot.
 6. The method of claim 1 wherein the materials accumulated within the slot are liquids.
 7. The method of claim 1 wherein said gas forced through the slot is air. 